1. Field of the Invention
The present invention relates to a lens apparatus which is used by being mounted onto a camera.
2. Description of the Related Art
Japanese Patent Laid-open Nos. 2005-266717 and 2005-352281 disclose a lens apparatus used as a camera system which records a moving image for a television broadcast.
In the lens apparatus disclosed in Japanese Patent Laid-open No. 2005-266717, each of optical adjustment function such as an iris (an aperture stop), zoom, IE, focus, and macro is controlled via a motor. Japanese Patent Laid-open No. 2005-266717 also discloses a tally portion which is controlled.
On the other hand, in the lens apparatus disclosed in Japanese Patent Laid-open No. 2005-352281, a tally lamp is turned on to inform a person who is an subject or a staff around of shooting an image using the lens apparatus and a television camera connected with it by turning on a tally lamp.
In shooting a program at a normal studio or broadcasting sports outdoors, a plurality of camera systems including the lens apparatus described above are used to shoot an image in many cases. In this case, commonly, a camera operator who operates each camera system and a person (an image selecting person) who selects an image to be recorded or broadcasted from a plurality of images shot by the plurality of camera systems are arranged at positions different from each other.
The camera operator of each camera system frequently performs a switch of an extender, a zoom operation, and a focus operation, in order to shoot a more powerful image by the camera system operated by the camera operator. Commonly, the camera operator obtains permission from the image selecting person before switching the extender.
However, when the number of the camera systems to be used is large, it is difficult to communicate between each camera operator and the image selecting person. Therefore, the image shot by the camera system during switching the extender, i.e. the image which is out of focus or includes the image of the switching of the extender may be selected to be recorded or broadcasted.
In some cases, a heater embedded in the lens apparatus may be operated in an image-pickup standby state so as not to lose transparency of the lens at the time of broadcasting in winter. However, when the zoom operation or the focus operation is performed without setting the heater to OFF in a case where it is necessary to suddenly start to shoot an image during the operation of the heater, a comfortable shooting cannot be performed due to the shortage of the power for the zoom operation or the focus operation.